Refractory sanitary ware setter

ABSTRACT

The invention relates to means for supporting ceramic materials in a kiln during the firing process, and more particularly to a supporting block for sanitary ware, which block is capable of being made by extrusion.

Unite States Patent [1 1 [111 3,764,261 Christman Get. 9, 1973 REFRACTORY SANITARY WARE SETTER [56] References Cited [75] Inventor: Brian B. Christman, New T D ST T S ATENTS Wilmington, Pa. 3,099,063 7/1963 Santhany 432/258 [73] Assignee: The Joseph Dixon Crucible Primary Examiner-John J. Camby Company Jersey Clty Attorney-James W. Block [22] Filed: May 18, 1972 [21] Appl. No.: 254,507 [57] ABSTRACT The invention relates to means for supporting ceramic materials in a kiln during the firing process, and more CCll. particularly to a supporting block for sanitary ware 58] Fie'm 132/258 261 which block is capable of being made by extrusion.

6 Claims, 1 Drawing Figure 1 REFRACTORY SANITARY WARE SETTER Due to the high kiln temperatures utilized in firing ceramics, the devices used for supporting the ceramic ware to be fired, variously known to the art as cradles or setters, are themselves fashioned of refractory ceramic material. These supporting devices, hereinafter called setter blocks, should be capable of rapid heating and cooling in order to avoid unduly long kiln cycling time. Their strength to weight ratio should be high for ease of handling and to minimize the kiln heat energy requirements since the energy required to heat the supporting devices is nonproductive. Setter blocks should be of symmetrical design and uniform wall thickness to minimize internal thermal stress as they are repeatedly heated to high kiln temperatures and cooled. Nonuniformities of shape and thickness give rise to uneven temperature distributions during heating and cooling, resulting in thermal stresses due to uneven expansion and contraction.

Sanitary ware such as toilet bowls have internal passages which should be exposed to the hot gas of the kiln atmosphere for uniform and rapid firing. Setter blocks having an aperture in the supporting surface for conveying kiln gas to the interior passages of the ware have been used for this purpose. U. S. Pat. No. 3,099,063 to Santhany discloses a setter block for such sanitary ware. The setter block is rectangular and includes apertures in the upper planar supporting surface for conducting heated kiln atmosphere gases to the interior portions of the sanitary ware when the ware is properly placed over the apertures. The Santhany block includes internal tubular supports at the supporting surface apertures. The tubular supports and the side and end walls of the Santhany block are provided with other apertures for conducting kiln gas to the interior of the block and thence to the apertures of the upper surface for communication with the interior of the ware to be fired. Such blocks have a relatively complex interior structure and must be cast using a technique such as collapsible coring to form the hollow interiors.

It is an object of the present invention to provide a sanitary ware setter block that incorporates a high strength to weight ratio while employing a uniform cross-sectional configuration so that it may be manufactured by an extrusion process.

The sanitary ware setter of the present invention is capable of manufacture by simple, rapid and inexpensive extrusion techniques. It does not require relatively cumbersome core casting or molding techniques. Because of its cross-sectional shape, the setter block of the present invention has a relatively high strength to weight ratio, resulting in a light but strong block offering case of handling and requiring a relatively low energy input for heating. The setter block is thus capable of relatively rapid heating and cooling, as the relatively uniform wall thickness and symmetry of shape minimize thermal stress for long life. Its high surface area to weight ratio also leads to relatively rapid heating and cooling, since there is a relatively great surface area exposed to heat transfer by convection, conduction and radiation. The setter block of the present invention also includes passages and apertures for encouraging the free flow of relatively large quantities of heated kiln gas to the interior of the sanitary ware being supported.

The drawing is a perspective view of a setter block according to the present invention.

As illustrated in the drawing, the setter block of the present invention includes a planar ware support surface 2 and a planar lower surface 4. The upper and lower surfaces are parallel to each other. Two longitudinal sidewalls 6 complete the block. The interior surfaces of the block define central longitudinal passage 8 having a generally elliptical cross-section. The exterior of each sidewall 6 is concave or curved inwardly. The sidewalls 6 are braced by oppositely curved wall segments 7. Thus, the sidewalls are each in the form of the region of a tangent intersection of two parallel hollow cylindrical segments. The interior and exterior surfaces of the sidewalls are each concave thereby making the wall biconcave in cross-section. The cylindrical sections diverge at the top and bottom leaving longitudinal passages 10 of generally triangular cross-section. The transverse ends of the setter block are also curved inwardly to result in a concave shape.

A plurality of apertures 12 traverse the sidewalls to allow hot kiln gas to communicate with the central longitudinal passage 8. The upper and preferably both of the planar surfaces 2 and 4 possess an aperture 16 in communication with the central longitudinal passage 8 to conduct hot kiln gas from the interior of the block to the interior of ware set over the aperture 16. The concave configurations of the sides and ends promote kiln gas circulation among a group of adjacent setter blocks. The concavity of the sides and transverse ends of the setter blocks form passages between abutting adjacent blocks which assure access of the hot kiln gas to the longitudinal passages 8 and 10. Further advantages of the concave side and end shapes are the prevention of outward bulging if the setter block softens during firing and a lessening of structural damage to the blocks if they are roughly handled.

The setter blocks of the present invention are fashioned of ceramic refractory materials for example of mixtures of ball and china clays, talc, calcined kyanite, and fireclay brick grog. The mixture is extruded through a die to form a long, soft extruded billet which is then cut into setter blocks of desired lengths. The cutting is preferably guided to result in a uniformly concave end shape. The still soft block is provided with apertures 12 in its sidewalls 6 and with apertures 16 in its planar surfaces 2 and 4. The apertures 12 and 16 can be cut with dies not unlike cookie cutters. The setter blocks are then dried and fired.

In use, sanitary ware is placed on the upper supporting surface 2 of the block and is positioned with its trap opening over the aperture 16. Hot gases from the kiln enter the central longitudinal passage 8 through the transverse ends and through apertures 12 in the sidewalls 6. The hot kiln gas atmosphere then passes through the upper surface aperture 16 into and through the sanitary ware interior passages. The block is reversible to offer two ware supporting surfaces thereby prolonging its utility.

I claim:

1. An extruded refractory setter block for supporting ceramic ware for kiln firing comprising upper and lower parallel planar faces and longitudinal biconcave sidewalls defining a central longitudinal open-ended passage, said sidewall including at least one aperture therethrough in communication with the central longitudinal passage for conducting hot gas from the kiln atmosphere to the longitudinal passage, andthe block having a longitudinally uniform transverse crosssectional configuration and an aperture through the upper surface in communication with said passage for conducting hot kiln gas from said longitudinal passage to ware placed on the surface of the upper face.

2. The setter block of claim 1 wherein the end surfaces of the sidewalls are curved inwardly.

3. The setter block of claim 1 wherein the sidewalls are in the form of a region of the tangent intersection of segments of two parallel hollow cylinders.

4. The setter block of claim 3 wherein the cylindrical segments forming the sidewalls diverge at the tops and bottoms of the sidewalls, the diverged segments thereby defining further longitudinal open-ended passages in the upper and lower regions of each of the sidewalls.

5. An extruded, hollow refractory setter block for supporting ceramic ware during firing, the block havmg: parallel planar upper and lower surfaces, concave side surfaces, concave end configurations, a longitudinally uniform transverse cross-sectional configuration, a longitudinal open-ended central passage, and at least one aperture in the upper surface in communication with the longitudinal passage.

6. An extruded hollow refractory settor block for supporting ceramic ware during firing, the block comprising parallel planar upper and lower surfaces and biconcave sidewalls; the block having concave end configurations, a longitudinally uniform transverse crosssection; a longitudinal, generally elliptical open-ended central passage defined by the interior surfaces of the sidewalls; additional longitudinal generally triangular open-ended passages located in the upper and lower portions of each sidewall; the walls defining the passages being of a substantially uniform thickness; an aperture through a sidewall in communication with the central passage for conducting hot gas to the central passage; and an aperture through the upper surface in communication with the central passage for conducting hot gas from the central passage to ware placed on the upper surface. 

1. An extruded refractory setter block for supporting ceramic ware for kiln firing comprising upper and lower parallel planar faces and longitudinal biconcave sidewalls defining a central longitudinal open-ended passage, said sidewall including at least one aperture therethrough in communication with the central longitudinal passage for conducting hot gas from the kiln atmosphere to the longitudinal passage, and the block having a longitudinally uniform transverse cross-sectional configuration and an aperture through the upper surface in communication with said passage for conducting hot kiln gas from said longitudinal passage to ware placed on the surface of the upper face.
 2. The setter block of claim 1 wherein the end surfaces of the sidewalls are curved inwardly.
 3. The setter block of claim 1 wherein the sidewalls are in the form of a region of The tangent intersection of segments of two parallel hollow cylinders.
 4. The setter block of claim 3 wherein the cylindrical segments forming the sidewalls diverge at the tops and bottoms of the sidewalls, the diverged segments thereby defining further longitudinal open-ended passages in the upper and lower regions of each of the sidewalls.
 5. An extruded, hollow refractory setter block for supporting ceramic ware during firing, the block having: parallel planar upper and lower surfaces, concave side surfaces, concave end configurations, a longitudinally uniform transverse cross-sectional configuration, a longitudinal open-ended central passage, and at least one aperture in the upper surface in communication with the longitudinal passage.
 6. An extruded hollow refractory settor block for supporting ceramic ware during firing, the block comprising parallel planar upper and lower surfaces and biconcave sidewalls; the block having concave end configurations, a longitudinally uniform transverse cross-section; a longitudinal, generally elliptical open-ended central passage defined by the interior surfaces of the sidewalls; additional longitudinal generally triangular open-ended passages located in the upper and lower portions of each sidewall; the walls defining the passages being of a substantially uniform thickness; an aperture through a sidewall in communication with the central passage for conducting hot gas to the central passage; and an aperture through the upper surface in communication with the central passage for conducting hot gas from the central passage to ware placed on the upper surface. 